GS750 back to nice.

[Drummert]

Rookie question: what's behind that right cover? Would I need to drain the oil before removing the cover to clean the oil window? You mention a gasket which makes me think I would have to drain it. I have my stainless bolts ready to go.

About those discs between slide and throttle linkage...my carbs are "missing" them as well. I wonder if they were added in later years.

Behind that cover is the clutch, and the clutch on these bikes is a wet one. So yeah, there's oil in there. Drain it before you take the cover off.

I don't know how most gaskets are when the cover comes off, but mine was completely gone. So I would suggest you get a new gasket as well. They aren't that expensive.

When cleaning the oil inspector, I used a small toothbrush and some soap. Let it dry reaaally well.

 

[Drummert]

And yeah, I think the plates in the linkages are a later addition. I found some schematics which did not show them either.

 

[hannibal]

I also think you're missing the spring. I tried several times to remove the spring before I convinced myself that there were no springs in there. If all four look the same, I bet a PO left then out.

 

[hannibal]

Thanks for the answer on the right side cover. Guess it'll have to wait til the next oil change.

 

[Drummert]

Yeah, the spring was missing, so I put a replacement in.


Did some work on the bike today. Was able to get the exhausts off with the handy use of a creme-brulee burner to heat up the bolts. None of the other bolts snapped, so I'll only have to deal with the one in the 4th cylinder head. Luckily a neighbour walked past today and told me he was able to weld a nut on it and get the bolt out in that way, so no drilling out. Phew.

A funny thing happened: I removed the last bolt on the left exhaust downpipe and, as a joke, gave it a little tug in a way of saying: and now for the back end to come loose... the bike on the other hand was a step ahead of me and the complete left exhaust dropped to the floor. Apparently the bracket on the end of the exhaust had rusted through as well... And to think I drove around with that.

So I decided to scratch the idea of refurbishing my exhausts. It's gonna be a new system for me. The downpipes I have are in a miserable state and I expect them to rust through soon, the mufflers are dented and the left one is like a swiss cheese. I found a shop near where I live that specializes in making exhaust systems for vintage motorcycle restoration projects, so I sent them an email. We'll see what they have to offer.


I must say, up to this point this was the scariest thing to do on the bike. Especially when you start to turn the bolt around and have to put a little effort into it at first.
Anyway, here's some pictures:

Grandad and grandson next to each other (notice the creme-brulee burner on the right. You can fit it right between the pipes. A lot easier than a large propane burner.)


Beaten up left exhaust


Lucky me for finding out about this one on the driveway and not on the road


I already removed the outer right downpipe before I decided to pull them all.



And now let's find some new pipes.

 

[Drummert]

It took some time, but new progress!

First things first: that one last bolt that needed to go out... It didn't. Me and my neighbour tried to weld a nut on there. After a couple of tries we stopped, because we weren't making any progress. The next day I spend the full day trying to drill the damn thing out, only to find myself with a 3mm indent at the end of the day. I called it quits on the bolt and called the shop.
The bike came back a week later, without stuck bolt and I was finally (!) able to mount the new exhaust. I decided on a 4-1 Motad in the end. Mounting was rather easy, so I put in a new battery and thought I would finally hear the bike run again.

Not. Here's the thing:

Fuel is going to the carbs. Petcock seems to work fine.
Starter engine turns over.
--> looking at the point I found a spark only at the right point.
--> No spark at the plugs...
I adjusted the valves, but have no idea if the timing of the points is OK now or how to check it.

So, with my humble knowledge, I would say something went wrong with the electronics over the course of 5 months, whilst the bike stood still. Rust or moisture maybe?
The important bit: what to check now? I saw some things already about the timing being off or the coils being bad but I have no idea how to troubleshoot this yet.
Maybe important as well: the bike did start before the exhaust overhaul. So something happened over the 5 months it stood still...

Anyway, picturetime, mounting the exhaust (picture of exhaust fully mounted will come):

 

[Drummert]

Update!

The bike has its exhaust fully mounted, I fixed the ignition with help from you gents and now the bike is running again.

So, its time for the next thing, which is: Front Fork. Basically, pitted forks = leaking oil seals = oil running towards the front brake = danger.
Now, I've read that a lot of people are fixing their forks taking them off, getting the rust out the pits with something sharp, putting epoxy in there , sanding it wet with grit 1200 and a sanding block, putting new oil seals and oil in and put it back together.

What do you guys think about this? Also: if they have to come of anyway, should I upgrade the springs in there as well and do the little trick with the spacer (apparently making the whole thing stiffer)?

As soon as this one's done, I'll do the front brakes and then the bike is roadworthy again (in my head it appears that I say this every single time to everybody within hearing range XD)

 

[steve murdoch]

The Progressive fork springs and a heavier weight oil, probably 15wt, will be a big improvement.
I have only heard of filling and sanding epoxy on the forks when it was a gouge or a nick. Not heard of it being used for rust pits.

 

[Drummert]

So the weather is becoming better and there is some money again. Time for an update. The last couple of months nothing really happened on the bike, so I am left much at the point where I was back then. Next up are the forks and the front springs.

I found a place where they can rechrome the tubes for between 75-100 euros per tube, depending on the state they are in. Since mine are quite pitted and rusted and I can't seem to find replacements this seems like an ok deal. I decided to go for the progressive springs to get the front end upgraded. Now the only thing remaining to do is to take it apart.

Now, the manual refers to the hexagon wrench and a front fork assembling tool, which I saw can also be replaced by using something like a 19mm bolt or nut welded to some rebar. What do you guys find easiest to use in this case?


In other news, my neighbour just bought a '81 GS850 which he has taken apart completely. Apparently, our little end of the street is starting to turn in a GS neighbourhood ^^

 

[jibledso]

I've been thinking of doing the same to forks on my GS it sounds like they are not as bad of shape as yours, I was considering getting the rubber according looking fork boots, kind of like the ones in the Honda CBs.

 

[Drummert]

Yes, I'm getting those as well. Looks ok, but keeping the tubes nice and clean is higher on the list.

 

[Drummert]

So I took the forks off today. What I found:

- One leg was further in the triple tree than the other
- The bolts on the left side of the bike where quite often tighter than on the right
- My fender is badly rusted (my neighbour came to take a look and offered me his slightly better fender from his GS850, which he is not going to use)
- One of the forks was filled with pitch black oil and not having enough
- The other fork had even less oil in it and it was sort of greenish, so mixed with water? Smelled horrible..
- I need new bolts with allen heads for those oil drainage holes.

Anyway. I came back to my decision for the springs and am going for Sonics now. I'm going to take apart the forks somewhere this weekend or next week. As soon as that's done, those tubes go to the rechroming people.

 

[Drummert]

I did some work today again. I shamelessly copied this from the other thread ^^ Here are my findings, pictures below:

- There are springs in there measuring about 510mm, so those are not the standard ones. I think these are progressive springs, but no idea how old and in what shape... More on this after this list.
- There was no spacer in the forks. Is this actually right with the progressive springs or should that have been in there anyway?
- Both my dust covers were so dry, they broke taking them off.
- Underneath one of the dust covers, I found some very nasty smelling stuff what almost seems to be a piece of cloth? Or maybe hard residue from the fork.. I had to take it out with a screw driver.
- I didn't need the tool (as you guys already said). Clamping it in the workbench with a towel around it and loosening the allen head bolt underneath was all I needed.
- Everything is really dirty. Whats the best way to clean everything? I'm afraid using degreaser harms the teflon coating of the bushes.
- The tubes are badly pitted. I checked to see if it wasn't just dirt, but they are rusted and I need to get them rechromed. There is a bushing in the inner tube, right? How do you get those out? I wasn't yet able to and I don't want to harm them. But I guess they'll have to come out for the rechroming.
- How do I actually know of the teflon coating is still ok? Does it just need to look ok?

Also, I'll have to look for a good way to take the oil seals out without harming the forks and the bushing underneath...

With my finding of the, I'd guess progressive, springs already in there, I started to doubt whether I should replace them. They are not the standard springs anymore, are longer than the originals and I thought the bike did ride nice before the oil seal blew. On the other hand I have no idea how old they are and you guys seem to like Sonics better, which I regard as expert advice. I already sent an email to them and got a very nice response back from Rich who confirmed my found spring rate as well. Decisions, decisions...


Sorry for asking some stupid questions with obvious answers, but I'd rather get it right the first time than harm the bike and needing to find new parts ^^

Picture time! Springs already in there:






The mess hidden beneath the right dust cover.

 

[Rijko]

I'll have to look for a good way to take the oil seals out without harming the forks and the bushing underneath...

i have an unconventional way for you, this is not a joke
Remove the inner tubes.

take a small torch like your creme-brulee burner, and heat up the oil seal evenly.
This does not take more than 10 seconds or so ... and the oil seal
may catch on fire so have a cloth ready to put that out.
The oil seal will drop out reeeaally easy by itself or with the
slightest push from a small screwdriver when it is hot.
No need for tire irons or similar tools.

I found the trick using heat by accident when i placed a fork leg
in front of a heat cannon to warm it up for polishing in
wintertime and left it there too long.
Works like a charm.

 

[Rijko]

PM me if you want to have a phone call on this,
i can talk you through some stuff if you want.
Have a good address for re-chroming, too.

Groeten Rijk

 

[Drummert]

PM sent to you, Rijk!

 

[Drummert]

Update:

I did some work on the fron fork. Didn't really get far, but at least I'm finally doing some work on the bike again

Thread about the front fork problems I encounter here: http://www.thegsresources.com/_forum/showthread.php?246857-GS750E-front-fork-spring-overhaul/page2

New pictures:

Problem with the outer tube and the fork seal which was really stuck in there. Tried screws, gentle prying, heat, flat bolt with weight as hammer upwards.



Problem with the inner tube which has a bushing on the inside at the bottom, which has to come out for rechroming. Bushing sits inbetween two ledges it seems and I have no idea how to get it out...

 

[jsandidge]

It seems you are a victim of photobucket. We can't see your pics.

 

[Drummert]

So it seems... In that case:

Stuck fork seal

Bushing in inner tube

BUT: a friend of mine who previously worked in a motorcycle shop got the fork seal out, after a lot of elbow grease, using a heat-gun for 15 minutes and "gently" using a large crowbar. In his words "That was the most f* stuck thing I've ever encountered!":

 

[Drummert]

Update:

Jut brought the inner tubes to a rechroming service to get them hard-chromed again. I spoke with a guy there and the bushing on the inside of the tubes is not going to be a problem, since they close both ends. So, inner tube problem fixed AND outer tube problem fixed ^^

Now, to order all the new parts. Anyone know a good place for some nice fork gators?

Also, this is one of the fork seals as it is now, ouch!